Photovoltaic Module Soiling Map

National Center for Photovoltaics (NCPV) scientists and engineers have generated a
map that highlights soiling parameters of fielded photovoltaic panels at more than
80 locations—either soiling stations or photovoltaic sites—across the United States.

Last Update: October 11, 2017. The map will be updated when new data become available.

SRatio Range

0-0.94

0.94-0.96

0.96-0.98

0.98-0.99

0.99-1.00

Map Content

The map shows locations of PV systems ( markers) or soiling stations ( markers). Click on each site for the following information:

Years of operation

County where the site is located (Note: specific locations are not given because of
contractual agreements)

Soiling Ratio (SRatio): insolation-weighted mean of the daily ratios between the output
of soiled and cleaned PV devices

SRatio uncertainty

Soiling Rate (SRate): median of the daily rates of change in soiling ratio during
dry periods

SRate range: the 97.5th and the 2.5th percentiles of the soiling rate distribution

Methodology

The soiling parameters in the map below were generated using the following methodology: